usts which the chemist had separated, went
abroad alone, and hailing a fiacre, gave the driver the address of
Professor Carl Seigfried. The carriage of the Princess was always at
the disposal of the girl, but on this occasion she did not wish to be
embarrassed with so pretentious an equipage. The cab took her into a
street lined with tall edifices and left her at the number she had
given the driver. The building seemed to be one let out in flats and
tenements; she mounted stair after stair, and only at the very top did
she see the Professor's name painted on a door. Here she rapped several
times without any attention being paid to her summons, but at last the
door was opened partially by a man whom she took, quite accurately,
to be the Professor himself. His head was white; and his face deeply
wrinkled. He glared at her through his glasses, and said sharply, "Young
lady, you have made a mistake; these are the rooms of Professor Carl
Seigfried."

"It is Professor Carl Seigfried that I wish to see," replied the girl
hurriedly, as the old man was preparing to shut the door.

"What do you want with him?"

"I want some information from him about explosives. I have been told
that he knows more about explosives than any other man living."

"Quite right--he does. What then?"

"An explosion has taken place producing the most remarkable results.
They say that neither dynamite nor any other known force could have had
such an effect on metals and minerals as this power has had."

"Ah, dynamite is a toy for children!" cried the old man, opening the
door a little further and exhibiting an interest which had, up to that
moment, been absent from his manner. "Well, where did this explosion
take place? Do you wish me to go and see it?"

"Perhaps so, later on. At present I wish to show you some of its
effects, but I don't propose to do this standing here in the
passageway."

"Quite right--quite right," hastily ejaculated the old scientist,
throwing the door wide open. "Of course, I am not accustomed to visits
from fashionable young ladies, and I thought at first there had been
a mistake; but if you have any real scientific problem, I shall be
delighted to give my attention to it. What may appear very extraordinary
to the lay mind will doubtless prove fully explainable by scientists.
Come in, come in."

The old man shut the door behind her, and led her along a dark passage,
into a large apartment, whose ceiling was the roof of t